crab soccer is a game that we used to play back in elementary school during physical education. the class would be split into two teams, each opposing one another from the baselines at either side of the gym. the centre line would be stockpiled with foam rubber balls about 1 foot in diameter, and when the coach blows the whistle you scuttle around in a moving backbend, hands and feet on the floor but body up, parallel to the floor... you look like a crab, hence the name.